Stanisław August Poniatowski
Born into wealthy Polish aristocracy, Poniatowski arrived as a diplomat at the Russian imperial court in Saint Petersburg in 1755 at the age of 22 and became intimately involved with the future empress Catherine the Great. With her aid, he was elected King of Poland and Grand Duke of Lithuania by the Sejm in September 1764 following the death of Augustus III. Contrary to expectations, Poniatowski attempted to reform and strengthen the large but ailing Commonwealth. His efforts were met with external opposition from neighbouring Prussia, Russia and Austria, all committed to keeping the Commonwealth weak. From within he was opposed by conservative interests, which saw the reforms as a threat to their traditional liberties and privileges granted centuries earlier.
The defining crisis of his early reign was the War of the Bar Confederation (1768–1772) that led to the First Partition of Poland (1772). The later part of his reign saw reforms wrought by the Diet (1788–1792) and the Constitution of 3 May 1791. These reforms were overthrown by the 1792 Targowica Confederation and by the Polish–Russian War of 1792, leading directly to the Second Partition of Poland (1793), the Kościuszko Uprising (1794) and the final and Third Partition of Poland (1795), marking the end of the Commonwealth. Stripped of all meaningful power, Poniatowski abdicated in November 1795 and spent the last years of his life as a captive in Saint Petersburg's Marble Palace.
A controversial figure in Poland's history, he is viewed with ambivalence as a brave and skillful statesman by some and as an overly hesitant coward by others, and even as a traitor. He is criticized primarily for his failure to resolutely stand against opposing forces and prevent the partitions, which led to the destruction of the Polish state. On the other hand, he is remembered as a great patron of arts and sciences who laid the foundation for the Commission of National Education, the first institution of its kind in the world, the Great Sejm of 1788-1792, which led to the Constitution of 3 May 1791 and as a sponsor of many architectural landmarks. Historians tend to agree that, taking the circumstances into account, he was a skillful statesman, pointing out that passing the Constitution was a sign of bravery, although his unwillingness to organize a proper nationwide uprising afterward is seen as cowardice and the key reason for the Second Partition and the subsequent downfall of Poland. Provided by Wikipedia